import React, {Component} from "react"
import './index.css'

export default class App extends Component {

    // 全选checkbox的回调
    handleCheckAll = (event) => {
        this.props.checkAllTodo(event.target.checked)
    }

    // 清除所有已完成
    handleClearAllDone = () => {
        this.props.clearAllDone()
    }

    render() {
        const {todos} = this.props
        // 已完成的个数
        const doneCount = todos.reduce((pre, todo) => pre + (todo.done ? 1 : 0), 0)
        // 总数
        const total = todos.length
        return (
            <div className="todo-footer">
                <label>
                    <input type="checkbox" checked={doneCount === total && total !== 0} onChange={this.handleCheckAll}/>
                </label>
                <span>
                  <span>已完成{doneCount}</span> / 全部{total}
                </span>
                <button className="btn btn-danger" onClick={this.handleClearAllDone}>清除已完成任务</button>
            </div>
        )
    }
}
